Delivery Date Estimates at checkout

Following lots of "will this arrive in time for Christmas" enquiries in my shop I went on the hunt for an extension that would give estimated dates at the checkout for when a package would arrive based on the different shipping options I offer (Airmail, two day, one day, and next day guaranteed) and typical dispatch times. Kind of like what Amazon offer when you are going through the checkout there.

I've found a few extensions that allow customers to specify the delivery date, which aren't what I'm after and I think they're obscuring my searches, but nothing that seems to fit the bill yet. Does anyone know of an extension with the functionality I'm looking for?